CT scans are X-ray procedures that use sophisticated computer software to create high quality images that may be viewed as horizontal or vertical "slices" of the body. For gastroenterologists, CT scanning is particularly valuable for evaluating the liver, pancreas, pelvic area, small intestine and the blood supply to the gut.
Preparation for a CT typically involves drinking a flavoured liquid called "oral contrast" before the scan. Oral contrast helps to visualize the stomach, small intestine and colon. An intravenous (IV) line is usually started immediately before the scan. During the scan IV contrast will be injected. IV contrast is necessary to visualize blood vessels and is particularly important when the CT is performed to evaluate the liver and pancreas for tumors.
The scan itself takes only a few seconds. The patient slides through a large donut shaped ring that contains the x-ray array. Claustrophobia is generally not a problem.
Radiation exposure occurs during CT scanning. This is unavoidable. Your doctor will carefully consider whether the question being asked of the CT scan justifies the small dose of radiation necessary.
IV contrast may occasionally cause kidney damage. The risk of kidney damage is very low, but is increased for people who are taking metformin (Glucophage) at the time of their scan, who have reduced kidney function or who are dehydrated. Allergic reactions to the dye can also occur. Please tell your doctor if you take metformin, have kidney disease or have had an allergic reaction to iv contrast dye in the past. Drink plenty of water before and after a CT scan to maintain well hydrated.
Scanning centers provide detailed instructions for CT scan preparation at the time appointments are made. Questions regarding preparation should be addressed to the relevant scanning center.